Oil well surveying instrument



D. B. MONROE 2,057,787

OIL WELL SURVEYING INSTRUMENT Filed April 2, 1935 2 Sheets-Shea?l 1 INVENTOR. /y/fz .5. /Va/yaf D. B. MONROE 2,057,787

Filed April 2, 1955 2 Sheets-Sheet 2 INVENTOR. fW/H Si /w/y/Paf -Z- L ATTORNEY.

Get. 20, i936,

OIL WELL SURVEYING INSTRUMENT Patented Oct. 20, 1936 UITED STATES PATENT OFFICE 2,057,731 on. WELL sUnvEYme INSTRUMENT Daniel B. Monroe, Denver, Colo., assignor of twothirds to L. C. Terry and Fred M. Manning, both of Denver, Colo.

Application April 2, 1935, serial No. 14,263

6 Claims.

This invention relates to a surveying instrument for oil wells, and has for its principal object4 predetermined time interval make a record of both l the vertical degree and compass direction of the inclination of the well at any given point.

A further object is to provide a target perforating device in which the perforating needle will be withdrawn from the target after the perforatlY ing operation so that movement of the device will not injure the needle or the perforation.

Other objects of the invention are to produce a device of this character which will be rigid in construction to withstand the usual oil well condi- 2'0'- tions; which will have but a minimum of parts;

and which will be absolutely positive and accurate in operation.

Other objectsl and advantages reside in the detail construction of the invention, which is de- D signed for simplicity, economy, and eftlciency.

These will become more apparent from the followingdescription.

In the following detailed description of the invention reference is 'had..to. the accompanying u drawings which form 'a part hereof. Like numerals refer to like parts in all views of the drawings and throughout the description.

In the drawings1- Fig. 1 is a side elevation of the complete device 35 with the barrel thereof cut in section to show the interior elements.

Fig. 2 is an enlarged vertical section through the operating portion of the device illustrating the latter in the released position.

40 Fig. 3 is a similar section through the compass portion of the device illustrating the latter in the set position.

Fig. 4 is an enlarged (full size) detail plan view of the indicating target, looking on the line li-, t

Fig. e is a horizontal section through the inner 55 housing taken on the line @-3, Fig. 3.

The invention comprises an outer barrel I0 preferably of brass or other suitable non-magnetic material. An extension tube 50 is threaded into the upper extremity of the barrel Ill and extends upwardly therefrom a sufllcient distance to brace 5 and guide the barrel in alignment with the drill stem of the oil well into which the device is lowered. A guiding point I2 is threaded into the lower extremity of the barrel I 0. A supporting Aplug I3 is secured in the top of the extension tube 10 50 and provided with suitable means for attaching it to a lowering wire I4. A guide shield I5 is positioned about the wire I4 and threaded onto the plug I3 to guide the device past obstructions while being raised in the drill stem. A partition plate 52 is secured in the barrel I0 adjacent its upper extremity.

An inner housing II is slidably fitted into the barrel I0 and is supported therein between the partition plate 52 and the guide point I2 upon 20 suitable sponge rubber cushions 53. 'I'hese cushions are suiliciently large and resilient to protect the contained mechanism from jars or shocks while being raised or lowered in the well.

A bearing block I6 is supported in the upper 25 portion of the inner housing II upon a suitable. shoulder ring 5I and supports ball bearings I l which in turn support a weighted plumb bob I8. The plumb bob I8 depends from a bearing ball I9 which rests on the ball bearings Il. The bearings I'I and the ball I9 are covered and protected by a suitable bearing cap 20.

The plumb bob I8 contains a needle 2| having an accurately ground point which projects from the bottom of the plumb bob. This point swings immediately above an indicating target card 22 which is removably carried on the upper extremity of a combined compass sleeve and target support 23.

The compass sleeve 23' is vertically slidable 40 in the inner housing II, and contains a compass case 24 in which a, compass needle 25 is mounted upon a xed pivot pin 26. The compass case is secured to the compass sleeve 23, and the entire assembly -is supported in the inner housing II upon a link 21 which in turn is supported from a pivoted, spring actuated lever 28.

A -spring 29 constantly tends to swing the lever 28 about its pivot from the position of Fig. 3 to .that of Fig. 2. When the device is set, this move- -ment is prevented by an L-shaped trigger 30 vto tremity releases the lever 28 allowing -it to snap around almost a complete revolution until it strikes'a stop spring 33. j

In swinging, the lever 28 will move the link 21 rst upwardly until it passes its uppermost point, thence downwardly to the stop position of Fig. 2. 'I'his up and down action of the link 21 ,pushes theA entire compass housing upwardly I so that the-,indicatingitarget 22 will be forced against the 'point of the 'needle 2I to perforate the target. It then lowers the target to again releasethe indicating point of the plumb bob.

The swinging lever 28 is fixed upon the extremity of a key shaft 44 which terminates in a setting key 45. The latter provides a convenient finger hold for rotating the lever 28 against the spring 29 to a position behind the trigger 30.

A compass locking arm 34 surrounds the pivot 26 below the compass needle 25. The locking arm 34 is carried from a push pin. 35 and acts to force thecompass needle from its pivot against an upper stop member 36." The push pin35 is operated from a lever 31 pivoted on` a bracket extending downward from the compass case 24. A stop pin 38 extends across the housing I I in the path of the lever 31 so that as the compass case moves upwardly to perforate the target 22, the extremity of the lever 31 will strike the pin 38, causing the former to push the push pin 35 upwardly. This lifts the locking arm against the compass needle and clamps the latter tightly against the stop member'. The push pin 35 is held in either the elevated position of Fig. 2 or the lowered position of Fig.-3 by means of a rocking compression spring 39. The spring 39 presses against the side of the pin 35 and creates suflicient friction to prevent the latter from dropping the compass needle when the compass casev 24 returns to its lowermost position. It has been found that the holding action of the spring 39 is increased if the extremity Ythereof which contacts the pin35 is allowed spacefor vertical movement. Then when the pin is up and locking the compass needle, as shown in Fig. 2, the spring will be pushin'g upwardly and, when the pin is down, as shown in Fig. 3, the spring is acting .downwardly. The stop member 36 may-be supported in a glass cover plate 55 over the compass.

It'will be notedthat the compass case 24 is relatively deep and that `its glass' cover 55 is spacedv quite high above the compass needle. This allows vertical latitude for the needle to accommodate inclinations of the instrument when in use.

It is desired to call particular attention tothe construction of the plumb bob I8, and its supporting bearing.. The bob consists of'a central tube 40 about which is 'secured the weighted plumb bob proper I8. 'I he latter is conical in shape with its smaller extremity downward. The lower extremity ofthe tube 49 projects from the bob and is also tapered to a relatively pointed extremity. The upper extremity of the tube 49 projects above the bob and is threaded to be received in a threaded socket 4I, upon an extension of which, the bearing ball I9 is formed. The needle 2l extends entirely through the length of the tube 40, and contacts at its upper extremity with the bottom of the inverted socket 4I. A spring 42 constantly forces the needle upwardly. When the device is not in use, the tube 40 can be threaded downwardly in the socket 4I so as to bring its lower extremity over the needlepoint to protect the latter. When being set for use,

inclination by a series of concentric numbered circles as shown in Fig. 4. The cards are held upon a diaphragm surface 45 and are clamped in place thereon by means of a clamping ring 41. The upper surface of the clamping ring 41 is marked with degree marks as indicated by the lines and dots in Fig. 4. The upper edge of the compass sleeve 23 contains an index arrow H8 and the edge of the clamping ring 41 carries a registering arrow 49. 'Ihe inner housing wall is cut away or, skeletonized opposite the target and clock as shown in Fig. 1 to allow ready visibility and access to these parts of the device.

Operation.

Let us assume that it is desired to check the drill stem of a rotary rig to ascertain if it is deviating from vertical. The operator unscrews the guide point I2 and slides the inner housing from the barrel I9. He then removes the clampingring 41 and places a targetdisc 22 therein, positioning the target so that the north point thereof will come opposite the indicating arrow 49. He then replaces the ring 41 with the target on the upper extremity of the compass sleeve 23, with the arrow 49 opposite the arrow 48. This procedure insures the north point of the target being accurately positioned over the north point of the compass case 24. By means of the key 45, he sets the lever 28 behind the vtrigger 30 "and sets the clock so that it will bring the notch of the cam 32 ybeneath the trigger 30 after a suiiicient time interval has elapsed to. allow him to lower the instrument to the desired depth. f

'I'he various parts are then reassembled in the barrel I0 andthe latter is lowered into the drill stem usually on the measuring line of the rig, to-the drilling extremity thereof. The device is left at rest until the pre-set time interval has elapsed, to allow the plumb bob to come to rest. Atgthe expiration of this time interval, the notch in the cam 32 will release the trigger 30, allowing the lever 28 to swing so as to lift the target against the needle point to perforate y the former and so as to lift the compass locking sleeve 34 to lock the compass needle 25.

The device is now withdrawn from the well, and the inner housing is removed from the barrel I8. The operator notes the perforation made in the target 22 by the needle point and can instantly determine by means of the concentric circles the exact degree of inclination from vertical, if any. He can also read by means of the compass index on the target the exact direction of the inclination.

Devices have been tried in which a plumb -bob needle perforates a target. In some of these, the needle remained in the perforation after the perforating operation. During the side sway and shock caused by drawing the instrument from the well the target would often be so badly damaged as to render an accurate `reading impossible. If the target was of a material to resist damage then the needle would be damaged. If the needle were made sufliciently heavy to resist this damage it could not perforate a small accurate perforation. 'I'his device avoids all of this by instantly withdrawing the needle after the perforating operation.

It is preferred to place an annular rubber cushion about the upper edge of the compass locking sleeve 34 and on the lower extremity of the locking member 36 to avoid damage to the compass needle and to assist in holding the latter firmly locked in place.

It is preferred to mount the cam 32 on the hour sleeve of the clock 3| and to secure an index pointer 51 on the minute shaft thereof. The operator can then set the pointer 51 back any desired fraction of a rotation to obtain th desired time interval.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, Without departing from the spirit of the invention. i

Having thus described the invention, what is claimed and desired secured by Letters Patent 1s:-

1. In an oilwell surveying instrument of the class described, the combination of a laterally extending shaft; a slidable target support; a lever secured to and projecting fromsaid shaft; a connecting rod connecting said lver with said target support; means for rotating said shaft to cause said connecting rod to axially reciprocate said target support to and from a marking position; and means for releasing said lever at a predetermined time.

2. In an oilwell surveying instrument of the class described, the combination of a laterally extending shaft; a slidable target support; a lever secured to and projecting from said shaft; a connecting rod connecting said lever with said target support; means for rotating said shaft to cause said connecting rod to axially reciprocate said target support to and from a marking position; a trigger member in the path of said lever preventing operation of said means; and a clock-actuated device for releasing said trigger at a predetermined time. y

3. In an oilwell surveying instrument ofthe class described, the combination of a laterally extending shaft; a slidable target support; a lever secured to and projecting from said shaft; a connecting rod connecting said lever with said target support; means for rotating said shaft to cause said connecting rod to axially reciprocate said target support to and from a marking position; a clock-actuated cam; a trigger member resting on said cam and projecting into the path of said lever, said cam being provided with a notch for releasing said trigger so as to allow said means to reciprocate said target support; and means for stopping the rotation of said lever after a complete reciprocation of said target support.

4. In an oilwell surveying instrument of the type described, the combination of a cylindrical, piston-like target support slidable within said instrument; a removable target on the top of said target support; a laterally extending shaft below said target support; a crank lever secured on said shaft; a connecting rod extending from an eccentric position on said crank lever to said target support, so that rotation of said shaft will reciprocate said target support in said instrument to bring said target to a marking position and thence withdraw it therefrom; a spring urging said shaft to rotate in one direction; a trigger for withholding said shaft from rotation; a stop member preventing more than a single rotation of said shaft; and means for releasing said trigger after a pre-set time interval.

5. In an oil well surveying instrument of the class described, the combination of a slidable target' support; a rotatable shaft positioned laterally to the line of movement of said target support; a connecting rod eccentrically mounted with respect to said shaft and extending to said support so that the initial rotative movement of said shaft will force said support to a marking position and the remaining rotation thereof will withdraw saidsupport; a spring tending to rotate said shaft; a lever xed to said shaft; a trigger holding said lever against the action of said spring; a clock; a cam actuated by said clock and supporting said trigger in the path of said lever, said cam being notched so that at a predetermined time it will allow said trigger to move from the path of said lever to allow said shaft to make a revolution.

6. In a device ofthe class described, the combination of, a rotary member; a slidably mounted target support; a spring for rotating said rotary member; a connecting rod eccentrically, mounted with respect to said rotary member and extending to said target support; and means for releasing said rotary member at a predetermined time to allow the latter to make a partial revolution so as to force said target support toward a.

l marking position and withdraw it therefrom.

DANIEL B. MONROE. 

